Speaking on BioWare’s forums, community manager Chris Priestly discouraged referring to the next Mass Effect game as Mass Effect 4. “We have already said that the Commander Shepard trilogy is over and that the next game will not feature him/her,” he wrote. “The game does not have to come after. Or before. Or off to the side. Or with characters you know.”
Clarifying those remarks, BioWare Montreal’s Yanick Roy stated that “Thinking of the next Mass Effect game as Mass Effect 4 would imply a certain linearity, a straight evolution of the gameplay and story of the first three games.” According to Roy, there may be some recognition of choices made in prior games, but if so it would not be the thrust of the new story. Details about that story, he added may be several months away.
You’ll forgive me for tagging it Mass Effect 4 for lack of anything else to call it.